ZDL

ZDL is a launcher application originally created by Ryan Turner (BioHazard) for the ZDoom source port. First released in 2005, ZDL was created out of a need to have a robust launcher for ZDoom and derivates, and as a replacement for the increasingly out of fashion  command parameter. Because many ZDoom mods utilize dependencies, they have to be loaded in a specific order, which proves problematic when loading multiple wads using the often common method of dragging and dropping the PWADs onto the source port .exe file. ZDL, owing to its extreme ease of use and simplicity, quickly became very popular among ZDoom users, and even after BioHazard stopped developing the launcher in 2005, it inspired a number of forks and rewrites. Today, newer versions of ZDL remain highly popular as launchers even for other ports besides ZDoom derivates.

The original ZDL was created by BioHazard, with development starting in early 2005 and version 1.5 being the first public release, dated March 12, 2005. The project's pace would expand rapidly over the course of that year, with version 2.0 releasing on July 15, featuring a total rewrite, and version 3.0 releasing on December 2. From version 2.0 onwards, ZDL presents itself as a small window with a series of options, including:


 * A source port menu, where one or more source port executables may be selected.
 * IWAD listing, where IWADs may be loaded and then selected to play with the relevant mods.
 * PWADs and patches, which allows the player to load WADs or, as well as DeHackEd files or .CFG files. Arrows can be used to move each entry in the list in order to ensure the desired WAD load order.
 * Multiple options to quickly host or join a multiplayer game, as well as select the desired game mode for it (cooperative or deathmatch).
 * The ability to warp to any desired map upon starting the WAD, select the desired skill level, and also set frag limits, DMFlags and DMFlags2 for multiplayer games.
 * ZDL automatically saves and remembers all options upon closing the program, but it can also manually save a configuration file or also load an existing one from elsewhere.

30.d, released on December 10, 2005, would be the last version released by BioHazard. Following this, two more updates were released: the first, ZDL 3.1 by Michael Niggel (Risen) added native PK3 support to the application (beforehand PK3 files could be selected only through the "view all files" option, and also added keyboard support and fixed some bugs. Another minor update was made by Raymond Chi (WildGoose), dubbed ZDL 3.1a and dated March 16, 2009, which restructured the program slightly and fixed one more bug. This would be the last release in the ZDL 3.x series.

In 2007, Cody Harris (QBasicer) began work on a rewrite of the program, initially named ZDLSharp, with BioHazard's permission. While a rewrite from the ground up, ZDL Sharp remained extremely similar to the original in function, with its last version being 3.0.5.3, released on January 20, 2008. Following this, QBasicer would attempt another rewrite, deemed qZDL or QtZDL, but a series of delays due to being busy on other venues led to development on qZDL starting again on 2012, with version 3.0.5.8 released on May 23 being considered the first stable release of this new fork. Following this, QBasicer announced another rebranding to ZDL 3.2, based off qZDL, with version 3.2.2.2 being released on August 8, 2012. This would be the final version of ZDL to be developed by QBasicer, who later announced the end of the project and encouraged other people to create a new fork. In 2019, Lcferrum restarted development and on May 2 released version 3-1.1, based off QBasicer's last release with new improvements and fixes. As of September 2023, this is considered the latest version of ZDL.